Various electronic products, especially portable electronic products, such as mobile phones, notebook computers, tablet computers/panel PC, personal digital assistants (PDA), barcode identification system devices, radio frequency identification (RFID) system devices, and global positioning system (GPS) devices, are commercially available and in wide use. When compared with its identification-related counterparts, radio frequency identification (RFID) has advantages, such as long service life, high security, and all-weather operation. Radio frequency identification (RFID) advantageously features a longer sensing distance and a higher scanning speed than conventional barcode identification systems do (because barcode tags have to be identified one by one, whereas more than 200 radio frequency identification-enabled tags can be processed simultaneously). Hence, it is even predicted that radio frequency identification (RFID) can gain a portion of the market share otherwise occupied by barcode identification. As regards its system framework, a radio frequency identification (RFID) system includes an electronic tag, a reader, and a system application. A radio frequency identification (RFID) antenna is installed on the reader and designed to operate by electromagnetic sensing or by microwave technology. In general, no electric wave can penetrate a metallic barrier. Nonetheless, electric wave can divert and form a magnetic field. Hence, the RFID antenna design is typically subjected to a limitation, that is, a magnetic field has to shun any shielding effect that is likely to preclude the formation of the magnetic field, and in consequence it is necessary for the RFID antenna to be equipped with a shielding layer for blocking electromagnetic interference.
Presently, conventional RFID antennas are formed mostly from conventional coils or printed circuit boards (PCB). The conventional RFID antennas formed from coils or printed circuit boards are bulky. However, a conventional RFID antenna is typically installed on a PCB (and thus known as PCB-style RFID antenna) or on a lid (and thus known as coil-style RFID antenna.) Therefore, the RFID antenna installed on a PCB or a lid has to be covered with a large shielding layer for preventing electromagnetic interference, thereby incurring additional manufacturing costs. Accordingly, it is desired to provide an effective way of cutting the costs of a shielding layer used for preventing electromagnetic interference.